ArcAdiAhttp://dspace-roma3.caspur.it:80
The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Tue, 03 Mar 2015 12:43:36 GMT2015-03-03T12:43:36ZCAIXA: a catalogue of AGN in the XMM-Newton archive II. Multiwavelength correlationshttp://hdl.handle.net/2307/384
<Title>CAIXA: a catalogue of AGN in the XMM-Newton archive II. Multiwavelength correlations</Title>
<Authors>Bianchi, Stefano; Bonilla, N. Fonseca; Guainazzi, Matteo; Matt, Giorgio; Ponti, Gabriele</Authors>
<Issue Date>2009</Issue Date>
<Is part of>Astronomy & Astrophysics</Is part of>
<Volume>501</Volume>
<Pages>915-924</Pages>
<Abstract>Aims. The availability of large amounts of multiwavelength data allows us to perform an extensive statistical analysis to look for correlations between different parameters of AGN. The physical implications of these correlations, when considered within the framework of current AGN models, can be enlightening in the resolution of the problems and the open issues which still characterise this class of sources. Methods. We presented CAIXA, a Catalogue of AGN in the XMM-Newton Archive, in a companion paper. It consists of radio-quiet X-ray unobscured sources, which cover a range in X-ray luminosities between L2-10keV = 2.0 x 10(41) and 3.9 x 10(46) erg s(-1), and in redshift from z = 0.002 to z = 4.520. Here, a systematic search for correlations between the X-ray spectral properties and the multiwavelength data was performed for the sources in CAIXA. All the significant (>99.9%confidence level) correlations are discussed along with their physical implications for current models of AGN. Results. Two main correlations are discussed in this paper: a) a very strong anti-correlation between the FWHM of the H beta optical line and the ratio between the soft and the hard X-ray luminosity. Although similar anti-correlations between optical line width and X-ray spectral steepness have already been discussed in the literature, we consider the formulation we present in this paper as more fundamental, as it links model-independent quantities. Coupled with a strong anti-correlation between the V to hard X-ray flux ratio and the H betaFHWM, it supports scenarios for the origin of the soft excess in AGN, which require strong suppression of the hard X-ray emission; b) a strong (and expected) correlation between the X-ray luminosity and the black hole mass. Its slope, flatter than 1, is consistent with Eddington ratio-dependent bolometric corrections. Moreover, we critically review through various statistical tests the role that distance biases play in the strong radio to X-ray luminosity correlation found in CAIXA and elsewhere; we conclude that only complete, unbiased samples should be used to draw observational constraints on the origin of radio emission in radio-quiet AGN.</Abstract>Wed, 31 Dec 2008 23:00:00 GMThttp://hdl.handle.net/2307/3842008-12-31T23:00:00ZCAIXA: a catalogue of AGN in the XMM-Newton archive I. Spectral analysishttp://hdl.handle.net/2307/285
<Title>CAIXA: a catalogue of AGN in the XMM-Newton archive I. Spectral analysis</Title>
<Authors>Bianchi, Stefano; Guainazzi, Matteo; Matt, Giorgio; Bonilla, N. Fonseca; Ponti, Gabriele</Authors>
<Issue Date>2009-02</Issue Date>
<Is part of>Astronomy & Astrophysics</Is part of>
<Volume>495</Volume>
<Pages>421-430</Pages>
<Abstract>Aims. We present CAIXA, a Catalogue of AGN In the XMM-Newton Archive.It consists of all the radio-quiet X-ray unobscured (N-H < 2 x 10(22)cm(-2)) active galactic nuclei (AGN) observed by XMM-Newton in targetedobservations, whose data are public as of March 2007. With its 156sources, this is the largest catalogue of high signal-to-noise X-rayspectra of AGN.Methods. All the EPIC pn spectra of the sources in CAIXA were extractedhomogeneously, and a baseline model was applied in order to derivetheir basic X-ray properties. These data are complemented bymultiwavelength data found in the literature: black hole masses, fullwidth half maximum (FWHM) of H beta, radio and optical fluxes.Results. Here we describe our homogeneous spectral analysis of theX-ray data in CAIXA and present all the results on the parametersadopted in our best-fit models.</Abstract>Sat, 31 Jan 2009 23:00:00 GMThttp://hdl.handle.net/2307/2852009-01-31T23:00:00Z